What is a key characteristic of a simple stain?

A key characteristic of a simple stain is that it utilizes only one dye. This staining method is straightforward and is primarily used to enhance the visibility of microbial cells under a microscope by adding color to them. The application of a single dye allows for the observation of general cell shapes, sizes, and arrangements without the complexities introduced by multiple dyes or differential staining techniques.

Unlike differential stains that employ more than one dye to distinguish between different types of cells or cellular structures, a simple stain focuses on uniformly coloring the cells, making them easier to analyze. It is an essential technique in microbiology labs, especially for preliminary assessments and basic identification of microorganisms.